Seventy-five patients with AIDS and moderate to severe disseminated histoplasmosis will be studied. It is anticipated that 60 of these patients will be blood culture positive. Those patients who are enrolled with blood cultures which subsequently prove negative, but with other evidence of disease will be evaluated for clinical response and safety only. Patients will be randomized upon enrollment in a 2:1 ratio. Administration of study drug will be conducted in a double blind fashion. Those patients randomized to receive AmBisome will receive 3.0 mg/kg/d of Ambisome for a total duration of two weeks. Patients randomized to receive amphotericin B will receive a daily dose of 0.7 mg/kg for two weeks. A 50% dose of study drug will be permitted on day 1, at the physicians discretion. Study participants will be observed daily and evaluated twice weekly during the induction phase.